puckered encodes a phosphatase that mediates a feedback loop regulating JNK activity during dorsal closure in Drosophila.
The activation of MAPKs is controlled by the balance between MAPK kinase and MAPK phosphatase activities. The latter is mediated by a subset of phosphatases with dual specificity (VH-1 family). Here, we describe a new member of this family encoded by the puckered gene of Drosophila. Mutations in this gene lead to cytoskeletal defects that result in a failure in dorsal closure related to those associated with mutations in basket, the Drosophila JNK homolog. We show that puckered mutations result in the hyperactivation of DJNK, and that overexpression of puc mimics basket mutant phenotypes. We also show that puckered expression is itself a consequence of the activity of the JNK pathway and that during dorsal closure, JNK signaling has a dual role: to activate an effector, encoded by decapentaplegic, and an element of negative feedback regulation encoded by puckered.
Martín-Blanco
E
E
Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
Gampel
A
A
Ring
J
J
Virdee
K
K
Kirov
N
N
Tolkovsky
A M
AM
Martinez-Arias
A
A
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D004330:Drosophila / Q000196:embryology* / Q000201:enzymology / Q000235:genetics; D029721:Drosophila Proteins; D005246:Feedback; D015971:Gene Expression Regulation, Enzymologic; D017344:Genes, Insect; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D008954:Models, Biological; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics; D010749:Phosphoprotein Phosphatases / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
D029721:Drosophila Proteins; D019476:Insect Proteins; C064196:dpp protein, Drosophila; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; C110854:puc protein, Drosophila; D010749:Phosphoprotein Phosphatases